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Turnaround operations at a fluid catalytic cracking unit at the Bloomfield Refinery (SIC-1799) in Bloomfield, New Mexico, were investigated for possible exposure of workers to various chemical agents, including hexavalent chromium (7440473), coal tar pitch volatiles (CTPV), nitrogen-dioxide (10102440), sulfur-dioxide (7446095), respirable dusts, and welding fumes. The average level of nitrogen-dioxide in the air was 1.5 parts per million (ppm); the value for sulfur-dioxide was 2.5ppm. NIOSH standards for hexavalent chromium (0.025mg/m3 for water soluble and 0.001mg/m3 for water insoluble) were exceeded. Respirable dust levels above 5mg/m3 were noted during cleaning operations. In many welding steps the concentration of welding fumes was in excess of 5mg/m3 as well. At the plasma arc cutting operation, concentrations of carbon-monoxide (630080), nitrogen-dioxide, and sulfur-dioxide (airborne) were 11.1, 1.5, and 2.5ppm, respectively. During the removal of coke from the reactor, CTPV levels exceeded the standard of 0.1mg/m3. A hydrocarbon concentration of 263ppm was obtained during the reconditioning of a pump. Nearly normal levels of 9.3, 45.7, and 74.1ppm were noted during more normal turnaround conditions. The author recommended that monitoring of the air be undertaken on a regular basis and that protective clothing and equipment be used by the workers. Ventilation rates and the direction of the ventilation should be checked.